Process of producing hydrogen.



A. MESSERSCHVHTT.

PROCESS of PRODUCING HYDROGEN.

APPLICATION FILED N. 9. 1915. LPQQED latented May 8, 191.7.

2 SHEETS-SHEET l.

1f Chienne? M? i@ M@ A. MESSERSCHVIH l.

PROCESS 0F PRODUCING HYDROGEN.

APPLICATloN FILED 1AN.9.1915.

l 5,2259254@ Patented May 8., 1917.

2 SHEETS-SHEET 2.

Tan sTriTus TriTnnT orrrcn ANTON MESSERSCHMITT, F STOLBERG, GERMANY,

IPBGCESS 0F PRODUCING HYDBOGEN.

meager.

Specification of Letters Patent.

@riginal applicaon le. June 26, 1912, Serial No. 706,118. Divided and this application led January 9,

1915. Serial No. 1,444.

A To all whom t may concern:

Be it `known that I, ANTON MESSER- sCHMrr'r, a citizen of the Empire of Germany, residing at Stolberg, in Rheinland, Germany, have invented certain new and useful Improvements in Processes of Producing Hydrogen, of which the following is a specification.

This invention relates to processes of producing hydrogen, and comprises alternate reduction and oxidation of ferruginous reaction material in such manner that it is uniformly heated to the requisite temperature whereby injurious secondary reactions resulting in separation of carbon, production of impure hydrogen, and fusing and caking of the charge, are avoided and whereby the maximum efficiency of the furnace is obtained with minimum consumption of steam and gas; all as more fully the reaction soon weakens, and at too low temperature ceases altogether. Another imhereinafter set forth and as claimed.

Usually theI reduction or oxidation process is performed by the retort process or by the producer process. Each of these has inherent disadvantages which it is the object of the present invention to overcome. In the retort process the reaction material, such as iron oxid, is contained inl a refractory jacketed iron retort which is externally heated. Overheating frequently occurs in the use of such retorts because extremely high temperatures are necessary to heat the material through the jacket, and when such high temperatures have been reached there is no way to control them, with a result that the reaction material frequently fuses to itself and to the retort walls and therefore not only obstructs the draft of gases but results in the necessity for removal from the retort walls. Unjacketed retorts, sometimes used have proved impracticable because at the high .temperatures required for the process they become damaged in a 'short period of time bythe action of the flame and the continuous oxidizing effect of the furnace gases. The producer process involves the use of retorts located in gas producers in such manner that the retorts are directly heated by the sensible heat of the ignited coke in the producer while water gas generated in the producer in the ordinary manner is admitted directly into the retorts in order to reduce the reaction material, the iron being subsequently oxidized with the production of hydrogen by means of ste-ani admitted into the retorts through separate pipe coils. Owing to the unavoidable and considerable temperature fluctuations of the coke charge incident to the operation of the producer and the combined attacks of heat, coke, slag, steam and air on the reaction material, the practical realization of this process has encountered insuperable difficulties.

In a modification of the producer process large chambers such as shaft furnaces, with direct periodic internal heating are used. Such process is subject to the disadvantages that it is practically impossible to uniformly heat the poorly conducting reacting material. 'Overheating frequently occurs in the material in the neighborhood of the heating zone while the remoterparts receive too little heat. In spite of strong heating, this procedure does not succeed in storing up sufficient heat in the ferrous charge, so that portant drawback of this process lies in the fact that the ferrous charge is made so impure by the large quantity of hot gases passing through, that it soon loses its activity.

Among other objects, this invention contemplates the eliminationv of the inherent objections of the retort and producer processes at the same time retaining their advantages.

The invention comprises a process wherein the reaction material is heated externally by heat passing through a conducting wall and at the same time by heat linternally conveyed by various draft currents, such draft currents being superheated outside the reaction furnace prior to entering the reaction material. The reaction'material in an externally heated vessel is alternately oxidized by means of a current of steam and reduced by a current of gas, and these currents together with liberated hydrogen, when it is formed, are caused to flow through heating yspaces in which high temperature heat is stored, on their way to and from the said vessel. ln one form of the invention a heating stage may be interpolated between the alternating oxidizing and reducing stages to maintain the temperature as required. And in still another' form of the invention the waste gases from the reducing vessel may be burnt in the heating spaces by means of air in order to assist in the heating procllO ess. The process may include periodic scavenging of the container for the reaction material and of the chamber or spaces wherein the heatis stored. This is accomplished by reversing the flow of the steam and gases or otherwiseI as more' fully hereinafter set forth.

In the accompanying drawings T have shown two forms of apparatus in which my process may be carried out.

Figure 1 is a vertical section of one form; and

Fig. 2 is a vertical section of a modication.

Referring first to Fig. 1: 1 indicates a heating chamber whichiis Ypreferably made of suitable refractory material adapted to withstand and to store the heat incidental to the process. This chamber is provided with a vertical preferably loosely buty air-tight connected reaction chamber or furnace in the form of a cylinder 2 having at its upper end the flange 3 which maintains it in deending position in the heating chamber 1.

ythis arrangement the regenerator is situated outside the reaction furnace, 'but is in communication with it. This reaction chamber is imperforate except at its lowermost end 5 wheregit is provided with a communication comprising cylindrical grating or screen which prevents the reaction material 'from falling into the heating chamber 4,

but which allows easy passage of the various draft currents. The heating chamber is provided with the refractory lining 6 comprising a checkerwork or labyrinth of `lirebrick or other ireproof material which converts the heating chamber into a superheating and heat storing inclosure.

The upper end of the column or reaction chamber 2 is provided with a charging opening which may be closed by means of 'a cover 7 The lower end of the heating chamber 4 is in communication with an air box 8 (having a cover 9) by means of radially projecting tubes or conduits 10 which have for their purpose to supply air from the box 8 to the heating chamber. 4. The box is closed at the bottom by means cfa removable cover 11 which 'is litted with a pipe connection 12 leading to a source of air under pressure. A gate valve 13 is provided for regulating l the air supplied to this box.

Arranged concentrically with the box 8 there is an annular gas casing 14 from which rise vertical pipes 15 and 16 adapted to supply gas to different levels in the heating chamber-4 These pipes 15 and 16 are uniformly distributed around the casing 14 and are so arranged that the long pipes 16 alternate with the short ones 15. Valves 17 operated from the outside serve to control the supply of gasto these pipes. This annular casing 14 1s 1n communication through a branch pipe 16 with the main 19 which communicates at 20 with the top of the reaction chamber or column.

The box 8 may be supplied with steam from a pipe 21 connected with the chimney From the main gas pipe 19 there branches i an auxiliary waste pipe 27, provided with a valve 28, and leadingl to a steam boiler furnace (not illustrated) or other place of use.

From the pipe 27, a pipe 29 branches downward into a vessel 30 provided with'a water seal. A pipe 33 serves for the removal of the hydrogen from the vessel 30.

In the use of the apparatus shown in Fig. 1 the furnace or chamber 4 situated outside the reaction furnace 2 is heated by combustion of gas derived from any suitable source through pipe 19,' the chimney register 31, the gas valve 26 and the air valve 13 being open. .The gas enters the heating chamber through pipes'l and 16 and is burnt by air from the radial pipes 10. The heat of combustion enters the reaction material which may be a ferruginous mass such as iron oxid, in chamber 2 by conduction through the wall. The waste gases escape through the open valve 31 into the chimney. As soon as the reaction furnace is at Ared heat, and the reaction material (iron oxid) inside the column 'at a corresponding temperature, the reduction of the material to form metallic iron can take place. By now opening the valve 32, purified reducing gases,l such as water gas, if necessary previously heated, are admitted through pipes 19 and 20 into the top of the column and pass downware. through the hot reaction material, reducing it. I

The waste gas escaping from the open lower end of the column passes upward through the heating chamber 4 outside furnace 2 and thence through the register 31 to escape. With suspended columns of the type shown this waste gas, particularly when it is combustible, is preferably burnt in the heatin chamber by means of air Vadmitted througi the pipes 10, and thus utilized in the heating.

On the other hand the reduction reaction can be carried out with a high degree of superheat of the reducing gases, by changing the direction of flow just stated and passing the gases through the pipes 15 and 16 into the heating space 4, air valve 13 being closed and the valve 26 open. The highly superheated reducing gases then arrive at the open lower end of the column and iow through the same, reducing material ico maneges after which they escape through pipes 20, 19 and 27 past the open` valve 28, to a steam boiler furnace in which they may be completely burnt.

The reduction process is preferably so conducted that the two directions of gas flow alternate, which greatly assists the-obtaining of a uniform heat distributionwithin the column, and therefore a uniform reduction of the whole of its contents.

When the reaction material is reduced to spongy iron, oxidation and production of hydrogen take place by means of steam, the

iron converted into ferrosoferric oXid, withy liberation of hydrogen. For thispurpose steam is now admitted to the box 8, by` opening the steam valve 25 and adjustment of the three-way cock 24, the gas and air valves being closed. The steam flows from the box 8 through the pipes 10 into and rises upward through the heating chamber 4. The chimney register 31 is kept open meanwhile in order that the gases filling the chamber and displaced upward can escape. After steam has blown through sufficiently to displace such gases the register 31 is closed. This leaves the chamber full of steam superheated by contact with the refractory material. The three-way cock 24 is now so adjusted that the steam flows through the pipe 23 to the top of the heating chamber and downward therethrough, forcing before it the very hot steam of the chamber. This steam, highly superheated by passing through the heating space, enters the column at its open and lower end and flows upward therethrough, forming hydrogen and oxid of iron. The liberated hydrogen in thecolumn is forced downward through the pipes 19 and 27 into the water seal vessel 30, (valve 28 being closed), from which after overcoming the pressure of the head of water, it passes away through the pipe 33 to a place of use or storage (not shown)e The apparatus therefore provides for the operation of this process consisting of a heating stage, a reducing stage and an oxidizing and hydrogen forming stage, the reducing and oxidizing stages alternating with each other regularly while the heating stage .may be interpolated'as often as required to keep up the temperature. Tf desired the heating stage can be combined with the reducing stage when admission of reducing gases takes place from the top in the manner above described andwhen the emerging gases are burnt in the heating chamber.

By inclosing the column in a closed gastight chamber, so that both the reaction space and the furnace space are practically in direct communication not only is a great pressure diderence between the column and the furnace obviated, thereby rendering leakiness of the former of no importance,

but also losses of hydrogen gas, which were very considerable in the retort process owing to the permeability of red hot iron to hydrogen and which took place on the slightest damage of the retorts, become quite impossible, since the red hot column wall does not constitute a partition between the hydrogen and the atmosphere, the cold outer wall of the furnace being the surface inclosing the apparatus from the outside. Hydrogen has a very rapid rate of diffusion. Tn this case however since steam surrounds and en ters the retortany pressure differential between the spaces inside and outside the retort does not tend to cause leakage of hydrogen.

Fig. 2 illustrates a type of apparatus, in which a cylinder 34 open at one end is fitted gas-tight to the bottom furnace wall, and a second cylinder 35 also open at one end and surrounding the cylinder 34 concentrically, is fitted gas ltight to the furnace wall, so that the outer chamber 37 is in communication with the inner chamber 38 through the reaction space 36. This forms two regenerators outside of the reaction furnace containing the charge, but in communication with such reaction furnace.-

Annular burner passages 39 are provided for heating the inner furnace space or stove. The inside of the stove is accessible through a door 4Q, and at the outer circumference of the furnace are provided doors 41 for the emptying of reaction material.

The furnace of Fig. 2 can be operated as follows. The reducing gas is first admitted to the outer space 37 (which has been heated as will hereinafter appear) by opening the gate valve 42. Gas fiows downward through the outer space 37 becoming thereby superheated, and thence into thev reaction space 36, and traverses the same upwardly reducing the iron. The waste gases then pass to the chimney through the open 'cover 44.

At the same time the inner superheated space 38 can be heated by internal combustion as required by opening gas valve 43 and admittin air by opening the air valve 46. Herea ter the cover 44 and the air valve 46 are closed, while the cover 45 is opened, the effect of which is that the gas admitted through the valve 43. flows upward through the hot checkerwork and the reaction column in reverse direction, that is downward, and escapes at the lower end of the outer cylinder, into the outer furnace space 37. By opening the valve 47 air is admitted to the annular chamber 48, whence it reaches the outer furnace space 37, so that the reducing gas issuing from the bottom of the reaction column is burnt to heat chamber 37. The waste gases escape through the cover 45 to the chimney.

For the production of hydrogen, the valve 49 is opened and the central superheated space 38 blown throughwith steam to scavenge it, the cover 44 being open. During this operation the valves 42, 47, 43, 46 and the cover 45 are closed. After the inner space 38 has been blown through, the cover 44 being closed, the cover 45 is opened, andl by opening the valve 50 and suitable adjustment of the three-way cock 51 steam is admitted through the pipe 52 to the lower part of the outer heating space 37 andI escapes from cover 45. After this steam has expelled all foreign gases,` the cover 45 is closed, the three-way cock 51 actuated to allow the steam to flow through the pipes 52, 53, 54 into the outer heating space 37. The steam superheated by passage through the heated space 37 enters the reaction space 36 at the bottom. rIhe hydrogen evolved escapes through the pipe 12 into a suitable receiver.

According to one method of operating this form of apparatus thehydrogen may be produced by passing purified reducing gas through the inner or first regenerator chamber 38, then through the reaction space 36. Oxygen or air containing` oxygen may be added to the gases leaving the reaction space and be passed while mixed with the gases through the second regenerator and there burned. Steam may then be passed through the first regenerator and then through the reaction space 36. Next purified reducing ygas maybe passed through the second regenerator 37, then through the reaction space and then -to atmosphere after admixture with oxygen to burn it. At the same time or subsequently additional gas or air may be admitted to the first regenerator by 43 and 46 and burned to heat 38. Air and gas may also be admitted to and burned in regenerator 37 by an arrangement similar to that shownin Fig. 1 wherein pipes 15 and 16 are located to supply air and gas at different levels. It is obvious that when gas passes from 38 through 36 then to 37, that air and other combustible gas may be added in 37. Steam may then be passed through the second regenerator and then the reaction space.

The apparatus 0f Fig. 2 has the advantage that owing to the arrangement of the iron charge in thin annular layers and the possibility of heating the said charge from two l u n 0 a sides, using a single reactlon charge, exceptionally large outputs of hydrogen can be obtained. Further there is derived the additional advantage ,that the interpolation of separate heating stages can be quite dispensed with, so that time is saved and consequently the output 0f the apparatus increased, and incidentally there is practically no limit to the size of apparatus that may be used `as `there will always be a relatively nar- -row annulus of reaction material in this y form of apparatus.

l The apparatus herein described for expositlon of the process forms part of the subject matter of an application led June 26, 1912, Serial No. 706,118. In that applica? tion I have shown three types of apparatus advantageous in the present process. Any form of apparatus may be used however, although that claimed ir the said application has been found to be particularly meritorions.

Vhat I claim is l. The process of producing hydrogen by alternately passing steam and a purified reducing gas over a ferruginous mass' and passing the steam and the reducing gas before they enter the reaction furnace through regenerators situated outside the furnace and passing the reducing gas, after it leaves the said furnace, in admixture with oxygen, through one of the said regenerators, thereby raising the temperature of the said regenerator.

2. The process of producing hydrogen by alternately passing steam and a purified reducing gas over a ferruginous mass and passing the steam and the reducing gas before they enter the reaction furnace through regenerators situated outside the furnace and passing the reducing gas, after it leaves the said furnace, in admixture with oxygen and other combustible gas, through one of the said regenerators, thereby raising the temperature of the said regenerator.

3. In the manufacture of hydrogen by the f the process which comprises maintaimng a pervious mass of such material in a container of heat-transmitting material in a combustion chamber, and alternately passing a draft current of gas through such mass to reduce it and thence into such chamber, v

burning it in such chamber to aiord the heat and passing a current of steam through such chamber to become heated and thence through such mass'to aord hydrogen.

5. In the manufacture of hydrogen by the alternate treatment of a mass of material comprising a metal of the iron groupy by draft currents of steam and reducing gases, the process which comprises maintaining a pervious mass of such ma?, ial in a container of vheat-transmitting material in heat-y reoeiving relationship to a combustion chamber having a checkerwork of refractory maferial, and alternately reducingy and rerasante oxidizing the material of the pervious mass with appropriate draft currents, in the reduction phase a draft of gas being passed through the pervious mass and then burnt with air in the combustion chamber and in the re-oxidizing phase, a draft of steam being passed through the. heated combustion chamber and thence through the pervious mass.

6. ln the manufacture of hydrogen by the alternate treatment of a mass of material comprising a metal of the iron group by draft currents of steam and reducing gases, the process which comprises maintaining a pervious mass of such material in heat receiving relationship -to a--combustion chamber, passing gas through the mass to reduce it and thence through the chamber for combustion therein, displacing waste gases in the chamber by steam and then transmitting steam through the chamber and into and through the pervious mass for the production of hydrogen.

7. ln the manufacture of hydrogen by treatment of a mass comprising iron with alternate draft currents of reducing gas and steam, the process which comprises maintaining a pervious mass of such material in heat-receiving relationship to a heating chamber, periodically producing combustion in said heating chamber and during the time when such combustion is not occurring alternately passing a draft current of gas through such material and a draft current of steam through such chamber and into and through such material.

8. A process for the production of hydrogen, in which an iron charge in an externally heated vessel is alternately oxidized by means of a current of'steam and reduced by a current of reducing gas, and these reaction currents and the liberated hydrogen on their .way to and from the said vessel are caused to flow through heating spaces in which high temperature heat is stored and in which reducing gas has been burned of the heat. l

9. A process for the production of hydrogen, in which an iron charge in an exterto e'ect storagenally heated Vessel is alternately oxidized by means of a current of steam and reduced by a current of reducing gas, these reaction currents and the liberated hydrogen on their way to and from the said Vessel being caused to flow through heating spaces in which high temperature heat is stored, and between these alternating oxidizing and reducing stages a heating stage being interpolated as required to maintain the temperature of the heating spaces.

l. A process for the production of hydrogen in which an iron charge in an externally heated Vessel is alternately oxidized by means of a current of steam and reduced by a current of reducing gas,` these currents and the liberated hydrogen on their way to or from the said vessel being caused to How through heating spaces in which high temperature heat is stored, and between these alternating oxidizing and reducing stages a heating stage being interpolated as required to maintain the temperature of the heating spaces, and the waste gases from the reducing vessel bein `burnt in the heating spaces by means of sultably admitted air.

11. A process for the production of hydrogen in which an iron charge in an externally heated vessel of iron is alternately oxidized by means of steam and reduced by a reducing gas, these reaction gases and the liberated hydrogen on their way to ,and from the said vessel being caused to flow through heating chambers in which high temperature heat is stored, between these alternating oxidizing and reducing stages, heating stages being interpolated as required to maintain the temperature of the heating spaces, the waste gases lfrom the reducing Vessel burnt in the heating spaces by.

means of suitably admitted air, and the `iron reducing Vessel periodically washed internally and externally with reducing gas.

In testimony whereof, lf ax my signature in the presence of two subscribing witnesses.

' ANTON MESSERSCHMTT. Witnesses:

HENRY erna, Womnmn Hem. 

